Tesla Recalls Overheating Chargers

SAN FRANCISCO – Tesla Motors announced Tuesday, January 14, that the company sold almost 6,900 vehicles in the fourth quarter of 2013, bringing the total number of Model S's delivered worldwide during 2013 to 22,300. The news pushed the company's shares up by 16%.

In Tesla's quarterly report, the company's fourth quarter revenue exceeded guidance by almost 20%. The company disclosed the financial results a day after it announced a recall on the company's car chargers which could overheat, and in some cases, start a fire.

"While the number of incidents remains small, and Tesla's review to date points to the building receptacle or wiring as the primary cause of failed NEMA 14-50 adapters," Tesla said in the letter, "the Company has determined that a voluntary recall is appropriate as a precautionary measure."

The Calif.-based company stressed that almost all of the Model S cars covered by a recall announcement Monday already received in December an "over-the-air" wireless software update to prevent chargers from overheating.

A notice posted Monday by the NHTSA said 29,222 cars in the United States are affected by the problem.

While the company believes the over-the-air software update will fully address the problem, Tesla said in a statement Friday, "However, to provide additional protection for Model S customers, we have designed a new wall adapter with a thermal fuse."

A variety of factors such as corrosion, physical damage to receptacles, or inappropriate wiring or installation of electrical outlets can cause higher than normal electrical resistance when using the Universal Mobile Connector ("UMC") NEMA 14-50 adapters to charge Tesla Model S vehicles. When charging, higher than normal electrical resistance connections to external energy sources may cause excessive heating of the adapter.

In December 2013, Tesla released an over-the-air software update to address this issue, enabling the Model S onboard charging system to automatically reduce the charging current by 25 percent if it detects unexpected fluctuations in the input power to the vehicle.

This fully addresses the issue by substantially reducing the heat generated in any high resistance connections outside the vehicle.

Touting the company's over-the-air software upgrade capability, Elon Musk, Tesla CEO, tweeted Tuesday afternoon: "No Tesla vehicles are being physically recalled by Tesla." Later he added in his tweet, "The word 'recall' needs to be recalled."

Something here doesn't pass the smell test. If there is abnormally high resistance somewhere, then then the heating will occur exactly where that high resistance is, and NOT ELSEWHERE. Thus, if the high resistance abnormality is in the user's provided circuit, the overheating should occur only there, NOT in the internal guts of what should be a perfectly high conductivity, zero resistance, simple 240v NEMA Tesla plug adaptor. So why and how can a perfect zero resistance simple Tesla adaptor melt when the high resistance problem is asserted to be in the customer;s wiring?

It seems to me there is a fundamental issue when people are modifying the vehicle firmware and software that controls the safety systems and that may be subject to mandated safety updates ("recalls"). A hobby programmer cannot possibly know how their modifications will interact with all future hardware, software, and firmware updates. Perhaps, the personal software will be blown away by a software update, perhaps it will interact adversely. I think I'll confine my programming efforts to other venues.

Naturally, it always goes without saying, early adopter "zealots" will always put a positive spin on anything to do with the object of their zeal. So, instead of figuring that it would be practically impossible for the established automakers, who sell 100s of thousands of cars every MONTH, to make "house calls," the zealot makes it sound like government-subsidized Tesla, selling way fewer cars than that per year, is doing something extraordinary. Come now. Let's not gush.

The fact that the Tesla software can be updated remotely is both good and bad, right? Let's be consistent. This can be done to operating software in ANY new car, in principle, but most people seemed to think that it was a bad idea. Most people, in the past, thought it best to take the car to a garage, where the update can only be entered via the OBD-II physical port. Now that we're gushing, though, it's a different story. In principle, any update to any ECU in my GM could be transmitted via OnStar. (They already give the car periodic health checks remotely, via OnStar, so why not updates too?)

Finally, the idea that charging a Tesla can burn your house down is not something to be brushed off either. Filling the tank of your standard car, while in the garage, could also burn your house down. That's why we don't have gasoline pumps in garages. Presumably, to allow anyone to install a gasoline storage tank and pump in his garage, you'd have to pass some sort of stringent inspection. High current battery charging, of the type needed to transfer enough energy to power a car for more than a really short ride, is serious business. It's hardly a surprise that, meeting code or no code, careless homeowners may not know what to watch out for. How many people look inside their 230V receptacles to make sure they are sparkling clean, for instance? Or will Tesla also make house calls to do that?

Your understanding is absolutely correct. I would not argue with that.

As a safety measure, Tesla took an initiative to report that to NHTHA, and that "recall" notice was posted by NHTSA Monday this week.

But here is the thing.

Even if this overheating issue has everything to do with corroded wall sockets, the fact that Tesla was able to address the issue by changing software means, well, there was a way to fix this on the automotive side.

And by debating it was a physical "recall" or not, we are underestimating the very fact that there was something Tesla could have done in the first place to make this safer.

I think there may be some confusion. From my understanding, the reason for this "recall" was not to fix a problem Teslas had but to workaround a problem owner's could have with their home wiring. If a home's electrical was installed to code, the update or "recall" was unneeded. I understood it as a safety measure to protect owners from their own home's faulty wiring. Based on that understanding, this wasn't something that Tesla was liable to address, but they did it anyway. Please let me know if I have the wrong understanding here. The press release did not attribute anything with the car itself, but with the charging environment it was being connected to.

@caleb, people have been modifying their cars for decades. People "modify" their car's mileage so that they can cheat (on the age of their car0, or modify their speed so they can go faster, etc. etc. Such practices have been hazardous -- for safety reasons, as well as for protecting the value of one's car -- and carmakers have been fighting it.

Tesla is taking a page out of the High Tech World guidebook - make it easy for customers to update and fix bugs easily through a simple download. The word "recall" in this article should be the phrase "bug fix sw download". It sounds like Tesla has been doing some superior bad press damage control.

@DMcCunney, I love your friend's Tesla story. I've heard similar stories as well. The point is that Tesla is doing everything it can to establish its brand and please its customers. That's admirable.

That said, here's my argument about "recall" definition.

OK. You are right. Customers did not physically have to return the car -- hence it was not "recalled" as far as the definition of the word "recall" goes.

But motor vehicle "recalls" are issued because of safety standards. To me, by saying this car was NOT technically recalled, it is as though Tesla is saying that this overheating issue does not fall into the category of "defect." I find Musk's tweet clever but also that tweet makes him sound irresponsible. Just as a reminder, NHTSA only issues a "recall" when it finds the following.

The United States Code for Motor Vehicle Safety defines motor vehicle safety as "the performance of a motor vehicle or motor vehicle equipment in a way that protects the public against unreasonable risk of accidents occurring because of the design, construction, or performance of a motor vehicle, and against unreasonable risk of death or injury in an accident, and includes nonoperational safety of a motor vehicle."